Method of making glass fiber forming feeders and feeder formed thereby

ABSTRACT

A method of making feeder for supplying a plurality of streams of molten inorganic material to be attenuated into filaments is disclosed comprising inserting elements in apertures in a member; sealing said elements and member within a coating adapted to isostatically transmit pressure to said assembly; applying isostatic pressure to the hermetically sealed elements and member to mechanically join the elements to the member; joining the pressed member to other sections to form the feeder; installing the feeder at a fiber forming position to receive molten glass; and then energizing the feeder to fuse the elements to the member to prevent the unwanted passage of molten glass between said elements and said member, said elements having an orifice to permit the passage of molten glass therethrough to establish said streams.

TECHNICAL FIELD

The invention disclosed herein relates to the production of glass fibersand glass fiber forming feeders.

BACKGROUND ART

With the production of glass fiber forming feeders having anever-increasing number of orifices or tips to supply the streams ofmolten material to be attenuated into filaments, the need for effectiveand efficient systems for attaching the orificed tips or elements in theapertures in the discharge wall has also increased. Previously, theindividual projections or tips were welded to the discharge wall byconventional welding techniques, such as cold resistance welding,electron beam welding, laser welding and the like. In essence, each ofthese systems welded a single tip at a time. With fiber forming feedershaving as many as 4,000 or more tips, the welding process can be quitetime consuming. Further, there are other problems associated with thesystems which are well known in the art.

DISCLOSURE OF THE INVENTION

This invention pertains to a method of making an orificed discharge wallfor supplying a plurality of streams of molten inorganic material to beattenuated into filaments comprising: inserting elements in apertures ina member; hermetically sealing said elements and member within a coatingadapted to isostatically transmit pressure to said member and elements;applying isostatic pressure to the hermetically sealed elements andmember to mechanically join or attach the elements to the member;joining the member having said elements attached thereto to othersections to form a feeder; installing the feeder at a fiber formingposition to receive molten glass and then energizing the feeder to fusethe elements to the member to prevent the unwanted passage of moltenglass between said elements and said member, said elements having anorifice to permit the passage of molten glass therethrough to establishsaid streams.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a semi-schematic front elevational view of a glass textiletype fiber forming system.

FIG. 2 is a semi-schematic front elevational view of a glass wool orrotary fiber forming system.

FIG. 3 is an enlarged cross-sectional view of the discharge wall of thefeeder shown in FIG. 1.

BEST MODE OF CARRYING OUT THE INVENTION

As shown in FIG. 1, feeder 10, which is comprised of an orificed bottomor discharge wall 14 and other sections such as containment or sidewalls12 and end walls 13, is adapted to provide a plurality of streams ofmolten inorganic material, such as glass, through a plurality oforificed elements 85. Feeder 10, including discharge wall 14, iselectrically energized via terminals 15 joined to a suitable source ofelectrical energy (not shown) to heat the glass therein as is known inthe art. As shown, terminals 15 are joined to end walls 13, butterminals 15 may extend outwardly from bottom wall 14 if desired. Thestreams of molten glass can be attenuated into filaments 16 through theaction of winder 26 or any other suitable means.

As is known in the art, size applicator means 18 provides a coating orsizing material to the surface of the glass filaments which advance togathering shoe or means 20 to be collected as an advancing strand orbundle 22. Strand 22 is then wound into package 24 upon a collet ofwinder 26 as is known in the art. Thus, FIG. 1 schematically representsa "textile" fiber forming system.

As shown in FIG. 2, rotary system 40 is comprised of a flow means orchannel 42 having a body of molten inorganic material 44, such as glass,therein. A stream of molten glass 46 is supplied to rotary feeder orrotor 50 from channel 42, as is known in the art.

Rotor 50, which is adapted to be rotated at high speeds, is comprised ofa quill 52 and a circumferential fiberizing or discharge wall 54 havinga plurality of orificed elements 85 adapted to supply a plurality ofstreams of molten inorganic material to be fiberized. Such elements maybe flush with the exterior surface of the wall or project outwardlytherefrom.

In conjunction with rotor 50, a shroud 56 and circumferential blower orfluidic attenuation means 57 are adapted to fluidically assist in theattenuation of the streams of molten material into fibers or filaments60. A binder material or coating may be applied to fiber 60 by means ofbinder applicators 58 as is known in the art.

As is shown in the drawings, member 69 of the fiberization or dischargewalls 14 or 54 of the feeders 10 and 50, respectively, may be based upona laminate comprised of a refractory metal core 70 having an oxygenimpervious, precious metal sheath intimately bonded thereto by hotisostatic pressing (i.e., HIP) as is disclosed in my patent applicationSer. No. 200,677, filed on Oct. 27, 1980, which is hereby incorporatedby reference. Or, member 69 may be comprised entirely of any suitablematerial, such as a platinum and rhodium alloy which, for example, iswell known in the art.

Regarding the laminated member, such refractory metals are selected fromthe group of materials consisting of molybdenum (Mo), columbium (Cb),tungsten (W), rhenium (Re), tantalum (Ta), hafnium (Hf), titanium (Ti),chromium (Cr), zirconium (Zr), vanadium (V), and base alloys of suchrefractory metals. For example, an alloy of molybdenum, titanium andzirconium, known as TZM, has been shown to provide a superior laminatedwall for a fiber forming feeder when clad with a precious metal alloy ofplatinum and rhodium.

Particularly, the precious metals for first layer 78, second layer 79and/or elements 85 are selected from a group consisting of platinum(Pt), paladium (Pd), irridium (Ir), osmium (Os), rhodium (Rh), ruthenium(Ru), and alloys based on such metals. Included in the platinum alloysare H alloy and J alloy which are alloys of platinum and rhodium of90%/10% and 75%/25% composition, respectively. In essence, the laminateis comprised of a plurality of layers of material wherein one of saidlayers is a refractory metal, and another of said layers is an oxygenimpervious, precious metal, said plurality of layers being intimatelybonded together by the application of isostatic pressure and heat toform a unitary laminate. Or, the laminate may contain an intermediatediffusion barrier between the refractory metal layer and the preciousmetal layer as set forth in my co-pending U.S. patent application Ser.No. 452,274, filed on Dec. 22, 1982.

FIG. 3 depicts a portion of a discharge wall at a point duringfabrication according to the principles of this invention. As such,elements or tips 85 are positioned in apertures 71 located in member 69.Then an elastic coating 94 is applied to the assembled member 69 andelements 85 to hermetically seal the elements and member therewithin.The coating or material 94 must be capable of isostatically transmittingfluidic pressure to member 69 and elements 85, and the coating materialmust prevent the migration of the working fluid such as "oil" in a coldisostatic pressing unit, between the mating surfaces of member 69 andelements 85. As will be explained later herein, cold isostatic pressing(CIP) is preferred and such coating materials are preferably elastomerssuch as PVC.

Then, isostatic pressure is applied to the coated assembly sufficient tomechanically seal or join the elements 85 to member 69. As described inmy U.S. patent application Ser. No. 398,536 filed on July 15, 1982,which is hereby incorporated by reference, the pressed member andelements were heated in a furnace to fuse the member and elementstogether prior to joining the other sections to the member 69 to formfeeder 10. With that application of heat, the mechanically sealedelements and member are fused together to prevent the unwanted passageof molten glass between the elements 85 and member 69 of discharge walls14 and 54. Then the discharge wall was joined to the sidewalls and endwalls to form the feeder.

According to the principles of this invention, the intermediate heatingstep to fuse elements and member together is dispensed with. That is,member 69 having elements 85 CIP'ed thereto is joined to the remainingsections, such as sidewalls 12 and end walls 13 to form feeder 10 in theabsence of previously heating member 69 and elements 85 to fuse themtogether. Subsequently, feeder 10 is placed in "position", that is, inplace to receive molten glass for attenuation into filaments (e.g.,under a forehearth), and electrically energized to resistively heatfeeder 10, including member 69 to fuse elements 85 thereto, in situ, atthe start up of the feeder 10.

A glass fiber forming feeder 10 discharge wall 14 was fabricated from aplatinum-rhodium alloy plate or member 69 and a plurality ofplatinum-rhodium alloy elements or tips 85. As such, member 69 contained800 apertures which each received an element 85. Each of the elements ortips 85 where comprised of a sleeve 87 and a flange 89. An orifice 86within sleeve 87 extended from first end 88 at flange 89 to a second end91 along sleeve 87. As shown in FIG. 3, second end 91 was closed.However, it is to be understood that tips 85 may be supplied with anopen second end 91 such that orifice 86 extends completely throughelement 85.

The elements 85 were inserted into aperture 71 of member 69 such thatflane 89 was in abutting engagement with one side of member 69 and suchthat a portion of sleeve 87, including second end 91, extended beyondthe opposite side of member 69.

The loose assembly of elements 85 and member 69 was then dipped in aliquid bath of polyvinylchloride (PVC) to coat the exposed surfaces ofelements 85 and member 69 and to fill orifices 86 of element 85. Afterthe application of the liquid coating, a slight vacuum was applied toassist in the complete filling of the orifices 86 with the elastomericmaterial. The PVC or pressure transmitting media was then cured orsolidified to a pliable state to seal elements 85 and member 69 againstthe migration of the working fluid in the pressing unit therebetween.

The coated assembly was then placed in the oil bath of a cold isostaticpressing (CIP) unit, and a pressure of about 150,000 psi was exerted onthe coated assembly to mechanically seal or join the elements to themember. Care should be taken to insure that all the orifices 86 arefilled with media 94, because if the orifices 86 are not completelyfilled with the pressure transmitting media 94, the sleeves 87 maycollapse upon the application of the pressure. Since cold isostaticpressure or pressing was employed, the operation was carried forth atapproximately room temperature.

Subsequent to the application of isostatic pressure in the CIP unit, theelastomeric coating 94 was slit and removed from mechanically joinedmember 69 and elements 85. The second ends 91 of elements 85 were thenmachined to open orifice 86.

Then the sub-assembly, comprised of the mechanically sealed elements andmember 69, was suitably joined to sidewalls 12 and end walls 13 to formfeeder 10. Subsequently, feeder 10 was positioned beneath a supply ofmolten glass, such as a forehearth or foremelter, as is known in theart. That is, feeder 10 is installed in the refractory 5 of a fiberforming position 6 so that molten glass is supplied to feeder 10 forattenuation into filament 16. Terminals 15 are joined as suitable sourceof electrical energy and then power is supplied to gradually raise thetemperature of feeder 10 to the desired level as is done withconventionally fabricated feeders.

Preferably, the material of tips or element 85 has a coefficient ofexpansion greater than that of member 69. As such, upon heating orenergization of feeder 10, sleeves 87 of elements 85 tend to expand morethan the internal diameter of the apertures 71 of member 69 such thatsleeve 87 is even more initimately pressed into the portion of member 69to finding aperture 71.

In the foregoing example, the elements 85 were comprised of H alloywhile the member 69 was comprised of J alloy. Upon electricallyenergizing feeder 10, and thus member 69, the members 85 are fused tomember 69 at flange 89 and sleeve 87.

If member 69 is comprised of a laminate having a refractory metal coreas disclosed herein, feeder 10 is preferably surrounded in an inert gas,such as nitrogen, to prevent the oxygen containing atmosphere fromoxidizing the refractory metal core prior to the fusion of the preciousmetal element 85 to the precious metal layers 78 and 79.

The coating material should not be too fluid or pliable. That is, thecoating 94 should be sufficiently viscous to prevent the flow of thecoating between the elements 85 and member 69 which may prevent theeffective mechanical attachment of elements 85 to member 69.

Although in the foregoing example, the member 69 was completely encasedwithin the pressure transmitting coating 94, it is only necessary thatthe elements 85 and that portion of member 69 associated therewith beheremetically sealed by the coating. That is, other portions of member69 may be left uncoated.

According to the foregoing procedures, if a tip 85, as shown in FIG. 3,is employed, the flange 89 will be fused to one surface of member 69 andsleeve 87 will be fused to the portion of member 69 defining theapertures 71 associated therewith. Further, if the refractorymetal/precious metal laminate is employed as member 69, the sleeve 87 ofelements 85 will fuse to core 70 and layers 78 and 79 to seal therefractory metal within a protective layer of oxygen impervious,precious metal to prevent the oxidation of the refractory metal atelevated temperatures.

Also, it is to be understood that element 85 may be of any suitableshape, and, in particular, flange 89 may be dispensed with and/or thelength of sleeve 87 may also be substantially equal to the thickness ofmember 69 to provide a tipless orifice plate having orifices lined witha suitable material fused to the member 69.

To provide an effective mechanical seal between the elements and memberin the isostatic pressing step, it is preferred that the isostaticpressure applied be greater than or equal to the yield point of thematerial of the elements 85 at the temperature employed for the pressingstep.

With respect to the in-situ fusing of elements 85 to discharge wall 54for a rotor 50, the "energization" to fuse can occur when the hightemperature gaseous blast from burner/blower 57 heats wall 54 andelements 85 at initial start up.

From the foregoing, it can be seen that the present invention isapplicable to the joining of the precious metal elements to thelaminated walls or members as disclosed in, for example, U.S. Pat. No.4,342,577, issued Aug. 3, 1982, in the names of Mohinder S. Bhatti andAlfred Marzocchi; and/or U.S. Pat. No. 4,343,636, issued Aug. 10, 1982,issued in my name, which are hereby incorporated by reference.

It is apparent that within the scope of the present invention,modifications and different arrangements can be made other than asherein disclosed. The present disclosure is merely illustrative with theinvention comprehending all variations thereof.

INDUSTRIAL APPLICABILITY

The invention disclosed herein is readily applicable to the formation ofcontinuous and/or staple glass filaments.

I claim:
 1. In a method of making glass filaments wherein a plurality ofstreams of molten glass issuing from an orificed discharge wall of afeeder are attenuated into filaments, the improvement comprising saidfeeder being fabricated by:inserting elements in apertures in a member;hermetically sealing said elements and member within a coating adaptedto isostatically transmit pressure to said elements and member; applyingisostatic pressure to the hermetically sealed elements and member tomechanically seal the elements to the member; joining the pressed memberand elements to sections to form said feeder; installing said feeder ata fiber forming position to receive molten glass; and then energizingthe feeder to fuse the elements to the member to prevent the unwantedpassage of molten glass between said elements and said member, saidelements having an orifice to permit the passage of molten glasstherethrough to establish said streams.
 2. A method of making feeder forsupplying a plurality of streams of molten inorganic material to beattenuated into filaments comprising:inserting elements in apertures ina member; sealing said elements and member within a coating adapted toisostatically transmit pressure to said elements and member; applyingisostatic pressure to the sealed elements and member to mechanicallyseal the elements to the member; incorporating the pressed member intosaid feeder in the absence of heating the pressed member and elements tofuse said member and elements prior to such incorporation; and thenelectrically energizing the feeder to fuse the elements to the member toprevent the unwanted passage of molten glass between said elements andsaid member, said elements having an orifice to permit the passage ofmolten glass therethrough to establish said streams.
 3. The method ofclaim 2 wherein the pressure is applied approximately at roomtemperature and the pressure is greater than or equal to the yield pointof the material of the elements at such temperature.
 4. The method ofclaim 3 wherein the coating is an elastomeric material.
 5. The method ofclaim 4 wherein the coating is polyvinylchloride.
 6. The method of claim2 wherein said hermetically sealed elements and member are coldisostatically pressed.
 7. The method of claim 2 wherein said member is alaminate comprised of a plurality of layers of material wherein one ofsaid layers is a refractory metal and another of said layers is anoxygen impervious, precious metal, said plurality of layers beingintimately bonded together by the application of isostatic pressure andheat to form a unitary laminate.
 8. The method of claim 7 wherein therefractory metal layer is a material selected from the group consistingof Ti, V, Cb, Ta, Cr, Mo, W, Re and base alloys thereof and wherein saidprecious metal layer is a material of the group consisting of Pt, Pd,Ir, Os, Rh, Ra and base alloys thereof.
 9. The method of claim 8 whereinsaid elements are selected from the group consisting of Pt, Pd, Ir, Os,Rh, Ru and base alloys thereof.
 10. The method of claim 9 wherein saidelements have a flange sealed to said member and a sleeve extendingbeyond the member.
 11. A feeder for supplying molten streams of glass tobe drawn into filaments comprising:a member having a plurality ofelements positioned in apertures therein said elements beingmechanically sealed to said member by cold isostatic pressing; sidewallsections extending upwardly from said member; and end wall sectionsextending upwardly from said member, said member, sidewall sections, andend wall sections being joined together in the absence of heating saidmember and elements to fuse the elements and member together.